Historically, visits to an eye care center or ophthalmic clinic were based upon obtaining a measure of the patient's reading quality as a function of distance, color and text dimension. Then based upon these the patient was assessed using a wide variety of graduated lenses to provide a simple three value characterization for each eye of the appropriate lens to correct for common visual defects such as shortsightedness, long-sightedness, and astigmatism.
Today such visitations to an eye care center or ophthalmic clinic include the addition of a limited but ever increasing number of testing methodologies for the detection of eye health problems (for example: glaucoma, age related macular degeneration, macular edema, diabetic retinopathy, etc) and systemic health problems such as diabetes. Generally, each such test is performed by provisioning of a further evaluation station within the center such that the patient is moved along by staff to each evaluation station in turn. At each station the patient is required to hold their head in a steady position within a restraint, and to keep their eye open for extended periods whilst the specific evaluation is performed.
Such a requirement for multiple evaluation stations places constraints on the provisioning of such ophthalmic tests for patients to locations with significant floor area, requires the centers providing the services to invest heavily in capital equipment, and provides a psychological barrier to patients in having frequent check-ups and assessments. Furthermore, a single file must pass from system to system for storing of results therein or data of one patient ends up in another patient's file. Management of patient data is important if screening tests are to be meaningful. More importantly, each testing station provides medical information unique to its testing environment (instrument design, patient positioning, imaging field, etc.) which poses a significant barrier to integrating/correlating these multiple results (such as for example identifying identical locations in the eye from each test) for making clinical decisions. Finally, the unavoidable significant time delay between the acquisition of results from each station means that there could be some changes in the patient's status (for example: patient gets tired, walking has increased heart rate, nervousness increases blood pressure, etc.) which could affect the ability of the clinician to integrate the information provided by the tests to provide a clinical assessment.
One approach to managing patient data is to test a single patient at a time. In such a situation, all systems are unused except one. This is an inefficient use of resources. Unfortunately, for a very efficient use of resources, file management becomes extremely difficult with several tests performed on different patients in parallel.
It would therefore be beneficial to provide an ophthalmic instrument that allowed a plurality of ophthalmic tests to be performed upon a patient in a single sitting with a single sequence of measurements that did not require reconfiguration of the ophthalmic instrument during the sitting. Advantageously, such a single sequence of measurements provides for quick and efficient correlation of results from these different measurements and allows for the incorporation of weightings or adjustments into the analysis of one characteristic based upon measurements and analysis of another characteristic. This being feasible as these measurements are now associated with defined time differences, the time between measurements being reduced with such a single setting and single sequence of ophthalmic measurements, and the conditions of the measurements being more consistent than moving a patient between multiple test stations over an extended period of time.
Advantageously, if the correlation between measurements is of increased interest (for example when testing for a specific condition) then the sequence of tests within the ophthalmic instrument can be changed simply, such as with software reconfiguration of the testing sequence. Further, the ability to provide consistent time differences and testing conditions between different measurements allows improved correlation of the measurements not only within a single sitting but across the multiple sittings of a patient over time with their repeat visits in order to follow changes over time. Additionally, the defined time stamps of the different measurements allows the subsequent analysis of the measurement data for an additional or new characteristic at a later date, a potential which today does not exist.
Additionally, automating multiple measurements within a single sitting provides opportunities to opportunities to expand the provisioning of the tests based upon ophthalmic measurements, including but not limited to, blood flow, oxygen saturation, etc. and allowing these tests to be deployed outside ophthalmic centers into doctor's offices, dental offices, and even wider providing opportunities for enhanced diagnosis, early identification of diseases or conditions, reduced health care expenditures, and potentially saving lives.
It is therefore an object of this invention to provide such a beneficial method of providing within a single sitting multiple ophthalmic measurements providing enhanced correlation of the measurements and analysis.